Yazarlar

• Zengin, B.(2)
• Korunur, S.(1)
• Ulak, F. Sadan(1)
• Yilmaz, A.(1)
• Yılmaz, A.(1)

• MakaleYalnız künye2018Scopus SJRQ4/r/munzur/3252
  400 MHz NMR Study of Isotope Effects on Albumin in H2O/D2O Solutions

  Korunur, S.; Zengin, B.; Yılmaz, A.

  Abstract: Chemical shift measurements were performed for several percentages of H2O added to D2O, in several H2O/D2O mixtures without and with a single concentration of albumin, and also in a mixture of 0.1H2O/0.9D2O containing increasing concentrations of albumin. The chemical shifts of pure mixtures decreases with increasing fraction of pure water. This is closely related to isotope effects. The chemical shift corrected for isotope effects increases with percentage of H2O. The chemical shift obtained for the mixture of 0.1H2O/0.9D2O increases with increasing concentration of albumin. These increments are consistent with fast chemical exchange in H2O/D2O mixture. In conclusion, present study reveals the presence of isotope effect on albumin in H2O/D2O solutions, and demonstrates fast chemical exchange in D2O solutions with albumin in a different way.

  AtıfScopus1·WoS1·OpenAlex1

  İncele
• MakaleYalnız künye2014Scopus SJRQ4/r/munzur/4015
  NMR Proton Spin-Lattice Relaxation Mechanism in D2O Solutions of Albumin Determined at 400 MHz

  Yilmaz, A.; Zengin, B.; Ulak, F. Sadan

  T-1 values in pure D2O and D2O solutions of human serum albumin (HSA) were measured versus temperature. A formula was derived based on H-H interactions between the surface HDO and non-exchangeable protein protons. The formula was used to evaluate the average distance of the interactions (rav). The effective correlation times were then derived by replacing the experimental data in the formula. Short correlation times obtained for the solution with low HSA (0.02 g albumin for one ml of D2O) decreased from 53 to 29 ps, while longer times increased from 1.19 to 2.22 ns. They are of the order of a fraction of a nanosecond for the solution with high HSA (0.08 g albumin per one ml of D2O). The perfect consistency between the derived theory and experimental data indicates that the high-field 1/T-1 in D2O solutions of albumin is caused by dipolar interactions between the surface HDO and non-exchangeable protein protons. It also suggests that the effective correlation time of the surface HDO is of the order of the mean lifetime of short-lived surface water.

  AtıfWoS9·OpenAlex12

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